1. Field of the Invention
The invention relates to communication of information among devices connected via a bus or transmission medium. In particular, the invention relates to communication of information between processing and peripheral devices on a bus or network.
2. Related Art
Conventional systems require extensive hand shaking protocols to prevent message collision and disruption of data. Techniques which have been employed include token passing, collision detection multiple access techniques, request and acknowledge signal protocols, and processor interrupts to service data processor requests by peripheral requests by peripheral devices.
Each protocol process results in signal processing delays and data transmission and reception delays while information waits in a queue as bus contention is resolved. In addition, the circuitry required to perform such bus contention resolution functions and to establish such queues adds to the cost of processing and peripheral devices.
Furthermore, transfer of some information, such as video information, to a processor from a device such as a CD-ROM to a display card requires data compression. Such compression further adds to the cost and may degrade the quality of the information.